Basic Dos and Don'ts in Query Letter Writing

This might be the most succinct version of Dos and Don’ts of query letter writing. There are tons of great blogs that explains the process well. What I’m trying to do is to capture the most important parts and put it together in layman’s terms for easy understanding. I hope you'll find them helpful.

Dos

1. A query letter must include book information (Title, genre, word-count), a pitch (a mini-synopsis without the ending), and your credentials (pertaining only to writing/publishing).
2. The pitch has to introduce your protagonist and antagonist (if there’s any), the main conflict, what’s at stake, and what your protagonist must do in order to overcome this conflict. Be succinct. 
3. Include your contact information. Include your real name if you're using a pen name.
4. Check for any typos and grammar errors for this is a small example of your writing skill.
5. Follow submission guidelines of each literary agencies.
6. Make sure the agency is open to submission and does represent your genre. 
7. Address the agents by correct title and name.
8. Use basic fonts (arial, times, courier, etc.) sized 12 and use single space. 
9. Use all caps for your book title only.
10. Mention the conferences you’ve attended if you’ve met the agent there and have been told to query him/her.
11. Mention a referral from another agent, the agent’s client, or another author with successful publishing history.

Don’ts

1. Don’t go over 1 page. Keep it under 300-350 words. Be concise. 
2. Don’t attach any materials unless requested.
3. Don’t call or show up and pitch in person. That goes for pitching through Twitter or their blogs which is a big no-no.
4. Don’t list your biography UNLESS your credentials are a degree in creative writing, memberships in large conferences/associations, or a previous publishing history. You may include your non-writing degree if it’s directly related to the subject of your book. For example, if you’re writing a nonfiction about child psychology, then do include your Ph.D. in Psychology.
5. Don’t get cute in the letter with unnecessary compliments, jokes, or pictures. You’re trying to sell your book, not make friends.
6. Don’t use gimmicks such as funny or unconventional fonts.
7. Don’t underline, bold, italicize everything.
8. Don’t ask questions. For example: “What would your do if you found yourself....” Agents don’t want to answer questions. They only want to know what it is about.
9. Don’t write the query letter using your protagonist’s point of view. This irks many agents.
10. Don’t refer to yourself in 3rd person as if someone else has written it for you. 
11. If you’ve received a rejection letter, do not ask why. And do not re-query them until you’ve done enough revisions on your query letter and your MS (6 - 12 months).
12. Don’t query more than one agent in the same agency.
13. Don’t lie.

That’s the short recap of general Dos and Don’ts. Please read each agency’s submission guidelines for specific requirements. Most importantly, follow those guidelines. Remember, that your query letter is the only chance to pitch your book to an agent. Give them a clean pitch that will catch their eyes. If you need help with your query letter, I offer a query letter package on my editor website. Happy writing~